Troponin I
Troponin I is a protein released into the blood when the heart muscle is damaged. It is one of the most sensitive markers for detecting heart injury.
Category: Cardiac Markers
Also known as: troponin i, tnni, tni, cardiac troponin i, ctni, hs-tni, Trop I
Reference range: 0–0.04 ng/mL (Source: ABIM)
Standard unit: ng/mL
High values may indicate
High troponin I levels may indicate heart attack (myocardial infarction), myocarditis, heart failure, pulmonary embolism, or other cardiac injury.
Low values may indicate
Low or undetectable troponin I levels are normal and suggest no significant heart muscle damage.
Frequently asked questions
- What is a normal Troponin I level?
- A typical reference range for Troponin I is 0–0.04 ng/mL (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is Troponin I measured in?
- Troponin I is most commonly reported in ng/mL. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do Troponin I reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track Troponin I over time?
- Yes. Upload results from any lab and BloodId charts your Troponin I over time against its reference range, so you can see whether the trend is rising, falling, or stable.
Related biomarkers
Source: MedlinePlus, U.S. National Library of Medicine
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